It depends on the workload and app for sure, but in my experience, most of my services make a bunch of outgoing calls, usually HTTP, to different services, often in a single operation. Being able to do these in parallel, on the side, or via fork/join was pretty handy. For a simple Flask app that fronts a single db, sure, stick with wsgi, but I don't run into many apps like that anymore.

Maybe not, according to this: http://calpaterson.com/async-python-is-not-faster.html

All of the high performing results are running with servers written in C/C++ tho.

I think if we have a more performant ASGI server / event loop, the results might be different.